Heat exchanger



1965 c. A. HEUER 3,200,480

HEAT EXCHANGER Original Filed Sept. 30, 1959 3 Sheets-Sheet 1 FIG-IINVEN TOR. CHARLES ARCH/BALD HEUE/P A TTO/PNEV Aug. 17, 1965 c. A. HEUER3,200,430

HEAT EXCHANGER Original Filed Sept. 50, 1959 3 Sheets-Sheet 2 1N VENTOR. CHARLES ARCH/BALD l/[UEP FIG 5 XMAA A T TOR/Ml; V

Aug. 17, 1965 c. A. HEUER 3,200,480

HEAT EXCHANGER Original Filed Sept. 30, 1959 S Sheets-Sheet 3 DEIDCICICIummnn 42 unnmn DEIDEIDEI nununn 4 common uumuuu umumnu FIG-8 INVENTOR.CHARLES ARCH/BALD HEUEP BY W gafw ATTORNEY United States Patent3,200,480 HEAT ERICK-HANGER Charles Archibald Healer, East Alton, Iii,assignor to min Mathieson Chemical Corporation, East Alton, Iih, acorporation of Virginia Original application Sept. 30, 1959, Ser. No.843,483, new Patent No. 3,173,479, dated Mar. 16, 1955. Divided and thisapplication May 27, 1963, Ser. No. 292,176 4 Claims. (Cl. 29-1573) Thisapplication is a division of copending application Serial Number843,483, filed September 30, 1959, now US. Patent 3,173,479.

This invention relates to heat exchangers and more particularly to aone-piece unitary type of heat exchanger having portions thereof broughtinto juxtaposed relationship with fluid passage systems in each of saidportions constraining fluid to fiow in counter-current relationship.

Heat exchangers spirally wound into coils are desired because of theirpotential capacity and low material cost. In spite of these advantages,such spirally wound heat exchangers have not found favorable receptionin the heat industry due to their low efiiciency and low heat transfercapacity obtainable heretofore by conventional methods of fabrication.

However, in accordance with this invention, it has been discovered thatincreased heat transfer characteristics and efliciency may be obtainedfrom spirally wound heat exchangers by providing therein a plurality ofspaced fluid passageway systems flowing in successively alternatingdirections, and bringing adjacent port-ions of the exchanger, containingsuccessive fluid systems, in juxtaposed relationship -with each other.More specifically, this is accomplished by providing within the elementa plurality of aligned spaced passageway systems, wherein fluid insuccessive systems is constrained to flow in alternate directions, withalternate adjacent terminal portions of the systems interconnected toeach other. The element is then bent so as to bring adjacent passagewaysystems into juxtaposed relationship with each other whereby the flow offluid in one portion of the element will be countercurrent to the flowof fluid in an adjacent juxtaposed portion of the heat exchangerelement.

Accordingly, it is an object of this invention to provide a novel heatexchanger of unitary construction.

It is another object of this invention to provide a heat exchanger ofone-piece construction wherein adjacent juxtaposed portions of theexchanger constrain fluid to flow, in each portion, in counter-currentrelationship.

Still another object of this invention is to provide a novel heatexchanger adapted for use as a condenser in central air conditioningunits, such as in use for home air conditioners.

Other objects and advantages will become more apparent from thefollowing descriptions and drawings in which FIGURE 1 is a plan viewpartly in cross'section illustrating an example of a novel sheet-likeelement employed in one embodiment of this invention;

FIGURE 2 is an elevational view illustrating one embodiment of thisinvention formed from the element illustrated in FIGURE 1;

FIGURE 3 is a perspective view of the embodiment of FIGURE 2 in asubsequent step of fabrication;

FIGURE 4 is a view taken along the lines of IV-IV of FIGURE 3;

FIGURE 5 is an elevational view partly in cross-section illustrating onenovel application of the embodiment illustrated in FIGURE 3;

FIGURE 6 is a plan view of another sheet-like element employed inanother embodiment of this invention;

FIGURE 7 is an elevational view of the element illustrated in FIGURE 6;

FIGURE 8 is a plan view illustrating another embodiment of thisinvention formed from the element of FIGURE 6; and

FIGURE 9 is an elevational view illustrating the e bodiment of FIGURE 8.

Referring to the drawings, one embodiment of the heat exchangercontemplated in this invention, is formed from a flat sheet element 1fabricated from superposed sheets of metal which may be brazed orpressure-welded together to define between them a plurality ofindividual fluid passageway systems. A preferred method by which suchsheet-like elements may be obtained, is disclosed in a patent issued toGrenell, US. 2,690,002, granted on September 28, 1954. In accordancewith the method of the aforesaid patent, a pattern of weld-inhibitingmaterial is interposed between superposed sheets 3 and 4, such asaluminum, copper and the like, which are thereafter conveniently securedtogether, such as by spot-welding at the corners, to prevent relativemovement between them. The sheets are then welded together at theadjacent surfaces not separated by the weld-inhibiting material by hotrolling the secured sheets. Hot rolling of the sheets results inreducing the thickness of the combined sheets and elongating theresultant welded sheet element in a direction of rolling while the widthof the element remains substantially the same as the initial width ofthe component sheet. Welding of the superposed sheets in accordance withthis method results in a substantially solid sheet having an internalconfiguration of laminations corresponding to the pattern ofweld-inhibiting material employed.

The resultant sheet element may be further treated as by rolling to theultimate thickness desired, and/or by annealing to soften it and therebyrender it more amenable to inflation upon injecting within its unweldedportion suflicient fluid pressure for permanent distention thereof.

As illustrated in FIGURE 1, the weld-inhibiting material 2 was appliedin two distinct and similar patterns 5 and 6 in alignment with eachother and interconnected to each other; it will be seen that thepatterns 5 and 6 are substantial mirror images of each other, forreasons to become evident. Each of the patterns 5 and 6 traverses itsrespective portion of the panel sinuously transverse their direction ofalignment. The adjacent terminal portions of patterns 5 and 6 areinterconnected together at 7 by an unwelded strip also contained withinsheet element 1. The passageway system 6 is also provided at its freeterminal portion with an unwelded strip 8 extending to the edge of thesheet toform an inlet for the interconnected systems within sheetelement 1. In similar manner, the pattern of passageway 5 is alsoprovided at its free terminal portion with a connecting unweld-ed strip9 extending to the edge of the sheet element to form an outlet for theinterconnected systems within the sheet element. As can be clearly seenthe fluid in pattern 6 will flow sinuously in its respective portioncounter-current to the direction in which the liquid will sinuously flowin the portion of the panel containing pattern 5.

Although a specific design passageway has been illustrated in FIGURE 1it is to be understood that the internal system of cavitations, formedupon subsequent distention of the unwelded portions, should preferablyoccupy substantially all of the major portion of the panel in which itsrespective pattern of weld-inhibiting material is contained. Inaddition, it is also preferred that the cross-section of tubularcavitations be maintained relatively small so as to permit thedistribution of greater length of conduiting within their respectiveportions of the sheet unit element 1.

Subsequent to pressure-welding sheet element 1 is then aao eeo bent withany convenient forming tool to spirally wind the element, about acentral opening 11, into a coil having a number of convolutions equal tothe desired number of systems defined by the plurality of spacedpatterns of weld-inhibiting material. In this manner each successiveconvolution substantially embraces between its terminal portionssuccessively spaced passageway systems.

Accordingly, for the sheet element illustrated in FIG- URE 1, thespirally wound coil 11%) has two convolutions 12 and 13 each embracingbetween its terminal portions, one of the interconnected patterns ofpassageways '3 and 6. Also, it is preferred that portions of the sheetelement between adjacent convolutions, which with the exception of aninterconnecting means such as strip 7 are substantially free of anyunwelded portions, be provided with an offset 14 to bring the terminalportions of 15 and 16, and 17 and 18 of each convolution into asubstantially abutting relationship with each other. In this form, eachconvolution is provided with a substantially cylindrical configurationwith the most outwardly convolution 12 forming a substantiallycylindrical surface about the spirally wound coil 10. If additionalstructural support is desired in a spirally wound coil of FIGURE 2 theabutting terminal portions of each convolution may be appropriatelysecured to each other as by welding, or brazing.

As will be noted, each passageway system will lie substantially athwartthe longitudinal extent of its respective convolution. Also, the passageof fluid through the system of passageways provided in one convolutionwill be constrained to flow, both, in a direction transverse thedirection of coiling and in a direction counter-current to the flow offluid in the passageway system provided in an adjacent convolution.Although an offset is preferred between the terminal portions ofadjacent convolutions, in the spiralled coil, and has been indicated aspreferred, it may be omitted with advantage in certain applicationswhere an external fluid medium is desired to How in a spiral directionbetween adjacent convolutions toward the central opening 11.

In its preferred form the sheet element is also provided with aplurality of louvered transfer openings 19, forming an integral part ofan arrangement of the heat exchanger. Such louvered openings 19 may beformed by providing a plurality of aligned and spaced slits with theintermediate portions of the element between them deformed, withappropriate shaping, to extend at an angle out of the face of theelement. Preferably these intermediate portions are deformed to flareoutwardly, for example in a semi-conical form, out of the face of thesheet element with their enlarged openings directed toward a lateraledge of the element. These louvers may be in uniform sequence or in anystaggered relationship desired with their flared ends directed in anysingle or multiple direction depending on the type and degree ofturbulence required for a specific application in order to control theflow of an external fluid medium through the transfer opening and itsimpingement against successive convolutions of the coil.

Thus, in accordance with this invention in the specific embodiment ofFIGURES 2 and 3, the passageway system defined by pattern 5 will beentirely contained in the outer convolution 12 with an outlet 22extending to an edge of the convolution. Similarly the system ofpassageways defined by pattern 6 will be entirely contained in the innerconvolutions 13 with an inlet portion 23 extending to an edge at thefree terminal portion of the inner convolution. Each system ofpassageways and its respective convolutions are interconnected togetherat the bottom lateral edge 24, of the spiral coil, by a tubular conduit25 extending through the offset portion 14, between the inner and outerconvolutions.

After being bent into :a spiral form the unwelded portions orlaminations of the sheet element are inflated by subjecting them tosufficient fluid pressure so as to permanently distend them. Theseunwelded portions upon distention form a tubular conduit system 20corresponding to the interconnected patterns of lamination provided insheet element 1. Such distention of the unwelded portions of the sheetelement 1 may be unrestrained or the spiral coil may be placed within adie provided with appropriate recesses which present opposed rigidsurfaces in spaced relationship to the corresponding faces of eachconvolution. Alternately, sheet element 1 may also have its unweldedportions distended prior to being spirally wound into the coil, and aswith its spiral form, the sheet element, may be distended freely orbetween opposed rigid platens. As will be understood, distention betweenopposed rigid surfaces provides a flat-top configuration 21 to theconduit system 29.

The distended spiral coil heat exchanger as illustrated in FIGURES 2 and3 may be utilized as a condenser suitable for use in central airconditioning units by mounting the condenser with other conventionalcomponents of a refrigerant system, FIGURE 5, and with its inlet andoutlet at the bottoms, is mounted on base 26 on which is also mounted aconventional sealed motor-compressor unit 27 within the central opening11 of the condenser. This motor-compressor unit serves to dischargecompressed refrigerant by a suitable conduit system, not shown, intoinlet 23 of the spirally wound condenser 10. As in conventionalrefrigerator systems the motor-compressor unit and condenser 10 arefurther connected with a conventional evaporator plate, for example suchas those disclosed and discussed in the aforesaid US. Patent 2,690,002,so that, together, the various components provided a series flowrelationship, from the motor-compressor unit to condenser to evaporatorplate, for a refrigerant fluid therein. In this arrangement, thecompressed refrigerant gases are discharged, from the motor-compressor,into the inlet 23 of the spiral condenser 10 for cooling andcondensation therein. Thereafter, cooled and liquefied refrigerant gasesare discharged as a liquid from outlet 22, of the spiral condenser 10,into an evaporator plate wherein the refrigerant is evaporated andreturned to the motor-compressor unit.

Also, in the embodiment contemplated by this invention, the spiralcondenser 10, of FIGURE 5, has also disposed within its central opening10 a fluid impeller 28 structurally supported therein by any suitablemanner, as, for example, upon a conventional electrical motor having anextended shaft 30 on which are mounted conventional fluid moving blades31.

In operation the compressed refrigerant gases from the motor-compressorunit, are discharged into the inlet 23 of the inner convolution whereinthey are constrained to flow in a sinuous or serpentine manner upwardlyin the inner convolution; the gases then enter, by means of the internalconduit portion 25, the upper terminal portion of the conduit systemprovided in the outer convolutions through which they flow downwardly ina sinuous or serpentine manner to be discharged as the refrigerantliquid from outlet 22 at the lower edge of the outer convolutions. Aswill be noted, the gases in each convolution flow in counter-currentdirections whereby succeeded portions of the inner convolution confine aprogressively hotter fluid adjacent portions of the outer convolutionconfining a progressively cooler fluid.

As the compressed gases flow through the spiraled condenser 14), thefluid impeller 28 draws an external cooling medium, such as air, throughlouvered transfer openings 19 which appropriately direct the coolingmedium over the condenser and the motor-compressor unit 27 into thecentral opening 11 from which the cooling medium is discharged.

Thus, the spirally wound condenser of this invention provides a verycompact unit in conjunction with a motorcompressor unit, as illustratedin FIGURE 5, which is highly desirable from an installation standpoint,and,

which, in addition, provides a higher degree of heat transfor and higherefliciency. As will be understood, modifications of the passagewaysystems may be made to give other condensing conditions depending on thespecific application involved. For example, the condenser unit may beprovided in each convolution with a series of lateral tubes laterallyspaced within each convolution and interconnected by a header, or, asaforesaid, a greater or a lesser number of tube passes may be providedwithin each convolution.

FIGURE 6 illustrates another embodiment of the invention employing asimilar sheet element 35 provided with two separate and distinct hollowconfigurations 36 and 37 disposed in spaced and aligned relationship toeach other in separate portions 47 and d8 of sheet element 35. As wasthe case with patterns 5 and 6 of FIGURE 1, the configurations 36 and 37are substantial mirror images of each other. Each of the distendedconfigurations 36 and 37 are provided with inlets 38 and 39,respectively, and with outlets 4-0 and 41. These configurations are ofthe type commonly known as a wafile pattern obtainable by means wellknown in the art. Such patterns may be obtained by applying asubstantially square or a rectangular pattern of weld-inhibitingmaterial on a sheet of metal which pattern has within it spaced pointsdevoid of any weld-inhibiting material. After the superimposition of thesecond sheet on the first sheet and pressure-welding of the two sheetstogether, the resultant sheet element has a plurality of welds 42disposed at spaced points within patterns 36 and 37. For this particularembodiment sheet element 35 was distended out of only one face 13 withthe opposite face 44 remaining substantially fiat. The desired sheetelement 35 may also be provided with a plurality of aligned slots 45separated by a substantially solid strap of metal 46. These slots 45provide a convenient means for the thermal separation of spaced portionsof sheet element .35 containing distended hollows 36 and .37. This stripof metal 46 also provides a convenient means for structurally supportingand maintaining adjacent portions of the element in proper relationshipto each other.

In accordance with this invention, the sheet element 35 is then bentalong a lateral line extending between hollows 36 and 37 so as to foldover adjacent portions 4-7 and 43 of the sheet element upon themselvesand to bring the top of the distended surfaces 49 and 50, of hollows 36and 37, in contacting juxtaposed relationship with each other. Anysuitable inlet tubes 53 and 54 may be inserted with in the inlets 38 and39, respectively, and any suitable outlet tubing 51 and 52 may beinserted Within outlets 40 and 41, respectively, and brazed to theformed element for communicating relationship with the distended hollows 36 and 37, respectively. Each of the distended hollows 36 and 37 ofthe form are then connected by their respective inlets and outlets intoseparate fluid systems. This embodiment of the invention provides anintegral compact one-piece structure for the interchange of heat betweenthe separate fluid systems whereby the separate fluids flow through oneof the hollow distentions 36 and 37 in counter-current relationship.

Although the invention has been described with reference to specificembodiments, materials, and details, various modifications and changeswithin the scope of this invention will be apparent to one skilled inthe art and are contemplated to be embraced within the invention.

I claim:

1. The method of making an integral sheet metal heat exchanger of aspirally coiled configuration having a plurality of internal unjoinedportions in juxtaposed relationship to each other, the method comprising(A) interposing a plurality of continuous patterns of stop-weld materialbetween superposed metal sheets, said patterns being in aligned andspaced relationship along the length of said superposed sheets, each ofsaid patterns (1) having terminal portions disposed adjacent to oppositeedges of said superposed sheets, and (2) having at least one terminalportion joined to one terminal portion of a successive pattern;

(B) joining the adjacent surfaces of said sheets not separated bystop-weld material;

(C) spirally coiling said sheets about an axis transverse the length ofsaid sheets into a coil having a plurality of convolutions in spacedrelation to each other, wherein each successive convolution contains oneor" said patterns in juxtaposed relationship to a successive pattern;and

(D) oiT-setting said convolutions by bending said sheets betweensuccessive patterns on a line passing through the joined terminalportions thereof and extending in a direction transverse the directionof coiling, to bring terminal portions of each of said convolutions intosubstantially abutting relationship,

whereby fluid flow in said juxtaposed patterns will be constrained tofiow in counter-current relationship between their terminal portions.

2. The method of claim 1 wherein each of said patterns is applied to liesubstantially athwart the length of its respective convolution andsinuously traverse said respective convolution in a direction transversethe direction of coiling.

3. The method of claim 1 including the steps of providing a plurality oftransfer openings in the joined portions of said sheets spaced from saidmaterial, and bending said joined portions adjacent said openings to anangle therewith.

4. The method of claim 1 including the step of inflating the unjoinedportions Within said sheets with suflicient fluid pressure for permanentdistension thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,092,018 9/ 37Quarnstrom 29-477.7 X 2,768,508 10/56 Guyton 62-509 2,777,300 1/57Palmer 62-523 2,779,173 1/ 5 7 Wurtz.

2,848,200 8/58 Jacobs -170 X 2,856,162 10/58 Adams.

2,920,463 1/60 Gould.

2,924,437 2/60 Wilkins 165-170 X 2,926,003 2/ 60 Pulsiter.

2,957,679 10/60 Campbell 165-166 X 2,999,305 9/61 Reynolds 29-15733,034,204 5/62 Grenell et al 29-1573 3,045,330 7/62 Johnson et a1.29-1573 3,048,916 8/62 Gahlinger 29-1573 3,104,701 9/63 Iacoby 29-1573 XWHITMORE A. WILTZ, Primary Examiner. CHARLES SUKALO, Examiner.

1. THE METHOD OF MAKING AN INTEGRAL SHEET METAL HEAT EXCHANGER OF ASPIRALLY COILED CONFIGURATION HAVING A PLURALITY OF INTERNAL UNJOINEDPORTINS IN JUXTAPOSED RELATIONSHIP TO EACH OUTER, THE METHOD COMPRISING(A) INTERPOSING A PLURALITY OF CONTINUOUS PATTERNS OF STOP-WELD MATERIALBETWEEN SUPERPOSED METAL SHEETS, SAID PATTERNS BEING IN ALIGNED ANDSPACED RELATIONSHIP ALONG THE LENGTH OF SAID SUPERPOSED SHEETS, EACH OFSAID PATTERNS (1) HAVING TERMINAL PORTIONS DISPOSED ADJACENT TO OPPOSITEEDGES OF SAID SUPERPOSED SHEETS, AND (2) HAVING AT LEAST ONE TERMINALPORTIN JOINED TO ONE TERMINAL PORTION OF A SUCCESSIVE PATTERN; (B)JOINING THE ADJACENT SURFACES OF SAID SHEET NOT SEPARATED BY STOP-WELDMATERIAL; (C) SPIRALLY COILING SAID SHEETS ABOUT AN AXIS TRANSVERSE THELENGTH OF SAID SHEETS INTO A COIL HAVING A PLURALITY OF CONVOLUTIONS INSPACED RELATION TO EACH OTHER, WHEREIN EACH SUCCESSIVE CONVOLUTIONCONTAINS ONE OF SAID PATTERNS IN JUXTAPOSED RELATIONSHIP TO A SUCCESSIVEPATTERN; ABD (D) OFF-SETTING SAID CONVOLUTIONS BY BENDING SAID SHEETS